ILI9341 with touch, SPI problem

[jeffmer]

I have the display module working with a TTGO V1.0 ( 4M PSRAM) module driving a ILI9341 screen, using latest firmware 21-3-18

The display functions work fine, however, touch screen does not. If I deinit the display, I can get a micropython xpt2046 driver working with the touch screen, however, this does not work with the display initialised - neither display or screen works but generate no error reports.

The display and touchscreen drivers share SPI(1) as they do in TFT. I suspect this is a problem with the SPI driver but can get no further.

PS Keep up the good work, having a large heap is truly liberating.

[loboris]

Sorry for late reply. I couldn't reproduce the issue with displays I've tested.

Could you give more information about the display you are using and the initialization parameters?

[flcorley]

I'm having the same problem. Or at least I think its the same. I didn't try a separate xpt2046 driver. My configuration works with the arduino ide bur no touchscreen in upython. I'm using this ILI9341 display that has a xpt2046 touchscreen controller. I'm using an ESP32 dev board. This is what I'm using for an init line - tft.init(tft.ILI9341, width=240, height=320, miso=19,mosi=23,clk=18,cs=5,dc=2,rst_pin=4,tcs=21,hastouch=True, bgr=True) I copied it from the examples, substituting my pin numbers (and adding reset).

I also tried using tft.TOUCH_XPT tft.init(tft.ILI9341, width=240, height=320, miso=19,mosi=23,clk=18,cs=5,dc=2,rst_pin=4,tcs=21,hastouch=tft.TOUCH_XPT, bgr=True)

In both cases, the display works great but no touchscreen.

[patbeppo]

I have apparently the same problem as jeffmer. I am using a WEMOS LOLIN D32 PRO with a 2.4" TFT, connected to the 10 wire connector on the board. The TFT is controlled by an ILI9341 and the touch screen by an XPT2064. (https://wiki.wemos.cc/products:d32:d32_pro)

The display works fine even with SPI speeds up to 80Mhz on VSPI. I used your tftdemo.py to test. The touch panel does not work in the demo. Also calling tft.gettouch() always returns False, 0, 0. I tested SPI speed down to 100kHz: never worked. So speed do not appear to be the issue. Also the touchpanel calibration does not work: the screen comes up but it never reacts to my touches.

The touch panel does work if I use machine.SPI with the same pin configuration exept for not giving the CS-pin for the touch panel. I also noted that when running tftdemo.testt() that tp cs was high (measured with a multi meter; I do not have an osci...). If I set tp cs to low I can read from the touch panel by writing 0xb0 resp. 0xd0 resp. 0x90. Surprisingly tp cs does not need to be set high after sending the command byte. I can leave it low and keep reading...

From these observations I am susptecting that your code might not set tp cs low long enough or maybe not at all??? Could this have to do with routing of the tp cs pin? I looked through your C-code, but that is mostly beyond my level. I noticed however the following: In tftspi.c in touch_get_data you write that the touch device must already be selected. However, in the first line of executed code you none the less select it.

// get 16-bit data from touch controller for specified type // Touch device must already be selected //---------------------------------------- int IRAM_ATTR touch_get_data(uint8_t type) { /* esp_err_t ret; spi_lobo_transaction_t t; memset(&t, 0, sizeof(t)); //Zero out the transaction uint8_t rxdata[2] = {0};

// send command byte & receive 2 byte response
t.rxlength=8*2;
t.rx_buffer=&rxdata;
t.command = type;

ret = spi_lobo_transfer_data(ts_spi, &t);    // Transmit using direct mode

if (ret != ESP_OK) return -1;
return (((int)(rxdata[0] << 8) | (int)(rxdata[1])) >> 4);
*/
spi_lobo_device_select(ts_spi, 0);

ts_spi->host->hw->data_buf[0] = type;
_spi_transfer_start(ts_spi, 24, 24);
uint16_t res = (uint16_t)(ts_spi->host->hw->data_buf[0] >> 8);

spi_lobo_device_deselect(ts_spi);

return res;

}

Here is my initialization:

tft.init(tft.ILI9341, spihost=tft.VSPI, speed= 80000000, width=240, height=320, miso=19, mosi=23, clk=18, dc=27, cs=14, rst_pin=33, backl_pin=32, backl_on=1, hastouch=tft.TOUCH_XPT, tcs=12, splash=False)

[dvilelaf]

Could this be related? This guy reports he has a xpt2046 module working after swapping some bytes.